As a gesso proponent in general, and a Liquitex proponent in particular, I don't think I'd recomment their Super Heavy gesso. It's meant for thick application and sculptural or textural work. You apply it heavily, and it stays in the form that you apply it. You want ordinary gesso which which snuggle right down in a thin, even layer even if applied thickly. The current Liquitex packaging is either "Gesso" if white or "Colored Gesso" if otherwise. I use black, gray, and white.
If a craft store can obtain Liquitex Super Heavy gesso, which is sort of a niche product, surely they can order ordinary gesso from the same supplier. Good luck!
Allen